As the heat generated by the games being played in the Cactus and Grapefruit leagues slowly works it's way north, temperatures in the Frozen States begin to gently rise.
Soon, in April, the teams themselves will begin to migrate North, bringing their warmth to places like Toronto, Minneapolis, Chicago and Milwaukee.
Tempreatures will continue to rise until late August when the NFL begins it preseason schedule. Then in September as the NCAA Football season gets under way a noticable cooling trend will begin and leaves will change color.
By the end of October, baseball will have vanished for another season and we will sink into the depths of yet another winter as Football reigns supreme upon the land.
All of which just goes to support my theory that Baseball causes Spring and Summer and Football causes Fall and Winter.
The answer for global warming is obvious.
MORE FOOTBALL!!!!